Shown in this post is my successful outcome using Hall Effect Feed back.
I had problems with noisy pots ( probably because they were cheap pots
) and I decided to experiment with a Hall effect alternative.
The system I made works very well. Absolutely not noise or jitters coming from the feedback. I can now put a bit of Derivitive into my motion - and the motion produced is fantastic. - fast and accurate - rock solid ( I am please as you can probably guess
I produced the assemblies on my CNC Router. This produced accurate alignment of the gears. Though there was a little bit of adjustment required to get the gears meshing smoothly (I used some $6 plastic gears). The Hall Effect chip is an A1302. I used salvaged bearing from a printer. Cheap neoidium magnets (ebay)I also re-used the original pots (ebay) for the drive and mounting, so it fitted back on to the motors in exactly the same way as the original pots.
I will also consider using the pot housings again to make 180 degree Hall Effect pots fo joysticks or rudder pedals, etc. (no gearing required so everything could be mounted into the pot case!)
The photos are self explanitary: